As was just stated states differ. Only about 7 states have extremely strict and onerous rules. Nothing like Australia as most of what you described would ruled unconstitutional as its completely arbitrary and onerous. In Pennsylvania you can legally posses anything that is legal at a national level. Concealed carry is “shall issue” meaning the state must grant you a permit unless you are a convicted criminal. This is consistent with “innocent until proven guilty” that is a bedrock of the US judicial system. In the US laws interfering with natural rights (freedom of speech, religion, etc) usually require “strict scrutiny” to be allowed. Meaning the government has to show that the good significantly outweighs the bad and can connect the dots between the law and the desired outcome. This hasn’t been always been applied to the 2nd amendment because of political differences but I feel the next case to the Supreme Court will change that. Law makers would have to be able to prove the proposed laws would make a significant difference and not be arbitrary.
In regards to crime and the real threat, what the media conveniently ignores but is easily verifiable by looking at fbi.gov is that almost all the gun crimes in the US happen with black market guns and criminals shooting other criminals in the inter cities. When you have a population of 350M numbers can sound large outside the context of the total population.
The numbers of self defense incidents among legally armed people are hard to track as many are not reported unless someone gets shot. Estimates are as low as 40000-50000/ year upwards of 4 million. Since the late 80’s most states have made it easier to get a concealed permit. Concealed carry has increased exponentially. In that same time violent crime has decreased dramatically...so it didn’t cause Wild West shoot outs as many politicians and the media implied it would. As more people carry guns you will probably see more defensive uses. What you don’t see are licensed people committing crimes.
In Pennsylvania open carry is allowed but is rarely seen. I’ve actually never seen it. From a tactical standpoint it’s a poor strategy as it exposes your gun to a potential criminal to take or for them to consider in how they would attack you. No one walks around with rifles except in rare occurrences for political theater at organized political rallies ....but I’m assume the media in Australia shows that like it’s a common everyday all over. You could live in the states for decades and never once see that in person.....even in Texas
https://www.forbes.com/sites/paulhs...ked-about-defensive-gun-uses/?sh=74f766f8299a